Variable resistor



June 25, 1957 G. SHARIK 2,797,285

VARIABLE RESISTOR Filed Oct. 8, 1954 2 Sheets-Sheet 1 38 Fig.6 36

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June 25, 1957 G. SHARIK 2,797,285

VARIABLE RESISTOR Filed on a, ,1954 2 Sheets-Sheet 2 56 Fig.9

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IN V EN TOR.

George .Slmfi/f United States Patent VARIABLE RESISTOR George Sharik, Jersey City, N. J.

. Application October 8, 1954, Serial No. 461,139

4 Claims. (Cl. 201-51 This invention relates to an electrical element and more particularly to a novel variable electrical resistor formed of a pile of disks of a suitable metallic substance or of a nonmetallic substance which may optionally be coated with any suitable metal.

' The primary object of the present invention resides in the provision of a variable resistor in which the electric resistance thereof may be rapidly varied by the application of pressure upon the pile of disks.

Another object of the invention resides in the provision of a novel arrangement whereby a pile of disks may be suitably mounted within a housing and upon which pressure may be applied either automatically or manually to vary the resistance of the pile.

Still another object of the invention resides in the provision of an electrical resistance pile which has novel means for dissipating heat.

Still further objects and features of this invention reside in the provision of an electrical resistance pile which is highly efiicient in operation, simple and inexpensive to construct, and which may be made from various readily available materials other than carbon which is utilized to form most conventional resistance piles so as to permit greater pressures to be applied thereby permitting greater resistance for use and sensitivity.

These, together with the various ancillary objects and features of the invention which will become apparent as the. following description proceeds, are attained by this variable resistor, preferred embodiments of which have been illustrated in the accompanying drawings, by way of example only, wherein:

Figures 1 through 4 are perspective views of novel disks which may be incorporated into the resistance pile;

Figure 5 is a perspective view illustrating the disks arranged within the housing;

Figure 6 is a vertical sectional view as taken along the plane of line 66 of Figure 5;

Figure 7 is a horizontal sectional view as taken along the plane of line 77 in Figure 6 illustrating the construction of the housing;

Figure 8 is a perspective view of a pile of disks provided with aligned apertures for reception of a ceramic rod for alignment;

Figure 9 is a sectional view of a modified form of the invention showing the construction of the casing for a pile of disks employing a ceramic rod;

Figure 10 is a perspective view of a modified form of housing provided with novel cooling means arranged in conjunction with the pile of disks;

Figure 11 is a vertical sectional view as taken along the plane of line 1111 in Figure 10;

Figure 12 is a horizontal sectional view as taken along the plane of line 12--12 in Figure 11;

Figure 13 is a perspective view of a modified form of disk provided with a cruciform shaped aperture; and

Figure 14 is a perspective view of a further modified form of disk or plate adapted to be utilized as a resistance unit.

With continuing reference to the accompanying drawings wherein like reference numerals designate similar parts throughout the various views, it will be seen that in Figure 1 there is disclosed :a disk 10 formed of a comparatively thin cylinder or wafer of metal, non-metallic substance, or a non-metallic substance covered with metal, which non-metallic substance may be other than carbon. The disk is provided with flat planar faces. Another disk as is shown in Figure 2 and designated by reference numeral 12 may be provided with an aperture 14 through the center thereof. In Figure 3 there is shown a further disk 16 having a concave surface 18 as well as a convex surface 20. The disk 22 shown in Figure 4 is similar to the disk 18 in that it is provided with concavo-convex surfaces as at 24 and 26 and the disk 22 is also provided with a central aperture 28 therethrough.

In Figures 5 and 6 there is shown a resistance pile arranged within a housing 30 and employing alternatively disks 10 and 16 as can be seen best in Figure 6.

The housing 30 may be formed from any suitable nonconductive material and is generally cylindrical in shape preferably provided with an integrally formed base 32. The upper end as at 34 may be threaded for the reception of a cap 36 which may also be formed of insulated material if desired.

Threadedly secured in the cap is a shaft or member 38 provided with means as at 40 for manually turning the shaft 33. A cylindrical member 42 is welded or otherwise secured to the end of the threaded member 38 and bears against the upper of the pile of disks. Hence, upon rotation of the head 40, the cylindrical member 42 will be pushed downwardly thus compressing the pile of disks.

Elongated slots 44 are formed in the casing 30 and generally extend substantially with the disks 10 and 16 so as to provide means for ventilating and cooling the interior of the housing 30 and thus cooling the resistance elements. It is to be recognized that as the disks are com pressed, the electrical resistance of the pile of disks will be decreased.

Referring now to the form of the invention as is seen in Figure 8, it will be seen that herein the disks 12 and 22 are alternatively arranged and a ceramic rod 46 is so positioned as to extend through the aligned apertures 14 and 28. The ceramic rod 46 serves to align the disks and maintain the disks in alignment. The ceramic rod 46 maybe secured in any suitable manner as by an adhesive or the like, to the uppermost of the disks when the disks are arranged in a housing as is indicated at 48. The housing 48 is substantially identical with the housing 30 but is provided with an aperture 50 therethrough through which the ceramic rod 46 can extend when pressure is applied on the disks through the use of the cylindrical member 52 and the threaded member 54 upon rotation of the head 56. Suitable cooling slots as at 58 may be provided.

In Figure 10 there is shown a modified form of the invention. This form of the invention includes a housing 60 which is formed of a bottom member 62 having outwardly extending and Widely spaced standards 64 which have their upper ends threaded for reception of a cap 66. A threaded member 68 is threadedly received in the cap 66 and has a substantially cylindrical member 70 secured thereto which is adapted to contact the pile of disks upon rotation of the head 72 and thus compress or release the disks. Interspersed in the pile of disks are cooling disks 74 which are provided with suitable latches as at 76 therein so that the periphery of the disks 74 will lie substantially flush with the periphery of the bottom member 62 andthe standard 64. Further, the disks 74 can slide readily relative to the standard 64 which may be made from any suitable and preferably non-conductive material. The pile of disks may be arranged so as to incorporate a ceramic rod 78 if desired and may utilize the disks 10, 12, 16, 22, as well as the disks as at 80 in Figure 13, or the plate-type disk 82 in Figure 14. The cooling disks 74 provide an enlarged surface area for cooling purposes.

The disk 80 in Figure 13 is provided with a cruciform shaped aperture 83 therethrough forming substantially a triangular sector portions 84 which are angularly bent to form a convex surface as at 86 and an under-concave surface 88.

The plate-type resistance element 82 may be of triangular cross section and provided with an aperture 84 therethrough as can be best seen in Figure 14.

In use, the resistance elements can be easily controlled using the heads provided for that purpose and the resistance of the pile can be varied by manually applying the desired pressure or decreasing the pressure. It is to be recognized that a resistance pile of the type described may be used as a voltage regulator in any case where the amount of current or voltage is critical and it is very important in certain aircraft instruments. The controlling element may be so arranged so as to be operated by an electromagnet which is arranged to increase the pressure by rotating the threaded members or otherwise applying the pressure (not shown) when the voltage drops, thereby increasing pressure on the pile and reducing the resistance so as to increase the current flow or to apply less pressure when the line voltage is increased to thus increase the resistance and reduce the current flow.

From the foregoing, the construction and operation of the device will be readily understood and further explanation is believed to be unnecessary. However, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the appended claims.

What is claimed as new is as follows:

1. A variable resistance adapted to be subjected to pressure comprising a pile of disks, said disks being alternately provided with flat planar surfaces and with concavo-convex surfaces, said disks being positioned within an electrical housing, and means engaging said housing for applying pressure on said disks, said housing having elongated cooling slots therein substantially coextensive with said disks.

2. A variable resistance adapted to be subjected to pressure comprising a pile of disks, said disks being alternately provided with flat planar surfaces and with concavo-convex surfaces, and a series of enlarged cooling elements disposed intet 'acent said disks, each of said elements having an enlarged surface area for cooling purposes, said area not in contact with said disks substantially exceeding the area in contact with said disks.

3. A variable resistance adapted to be subjected to pressure comprising a pile of disks, said disks being alternately provided with flat planar surfaces and with concavo-convex surfaces said disks having said concavoconvex surfaces having a cruciform shaped aperture therethrough, the triangular sectors formed by said aperture angularly extending to form said concavo-convex surfaces, said disks being positioned within an electrical housing, and means engaging said housing for applying pressure to said disks, said housing having elongated cooling slots therein substantially coextensive with said disks.

4. A variable resistance adapted to be subjected to pressure comprising a pile of disks, said disks being alternately provided with flatplanar surfaces and with concave-convex surfaces, said disks being positioned within an electrical housing, and means engaging said housing for applying pressure on said disks, said housing having elongated cooling slots therein substantially coextensive with said disks, said means including a substantially cylindrical member engaging the uppermost of said disks, said housing having a removable cap, a threaded member threadedly engaging said cap extending through said cap and being secured to the cylindrical member, said threaded member when rotated causing said pile to be compressed between said cylindrical member and the bottom of said housing, said disks having aligned apertures therethrough, and an alignment guide post secured in said apertures, and a series of enlarged cooling disks interspersed between said other recited disks, said disks having said concavo-convex surfaces having a cruciform shaped aperture therethrough, the triangular sectors formed by said aperture angularly extending to form said concavo convex surfaces.

References Cited in the file of this patent UNITED STATES PATENTS 1,492,774 Boyton et al. May 6, 1924 1,521,213 Baruch Dec. 30, 1924 1,891,410 Greene Dec. 20, 1932 1,894,842 Appleberg Jan. 17, 1933 2,300,471 Smith Nov. 3, 1942 FOREIGN PATENTS 224,061 Great Britain Nov. 6, 1924 226,861 Great Britain Dec. 19, 1924 

